Glower-terminal for electric incandescent lamps.



N0. 6 512 6fi& Patented June 26, I900. M. W.- HANKS.

GLOWER TERMINAL FOR ELECTRIC INGANDESCENT LAMPS.

(Application filed Apr. 22, 1899. Renewed Apr. 28, 1800.)

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UNITED STATES MARSHALL WV. I-IANKS, OF PITTSBURG, PENNSYLVANIA, ASSIGNORTO GEORGE WESTINGHOUSE, OF SAME PLACE.

GLOWER- TERMINAL FOR ELECTRIC INCANDESCENT LAMPS.

srnoIFIcAtrIoN forming part of Letters Patent No. 652,609, dated June26, 1900.

Application filed April 22, 1899. Renewed April 28, 1900. Serial No.14,762. (No model.)

To all whom it may concern).-

Be it known that I, MARSHALL W. HANKS, a citizen of the United States ofAmerica, and a resident of Pittsburg, in the county of Allegheny andState of Pennsylvania, have invented certain new and useful Improvementsin Glower-Terminals for Electric Incandescent Lainps, of which thefollowing is a specification.

In electric lamps of the type now known as .Nernst lamps, wherein theilluminant-s or glowers are composed of the rare earths or mixturesthere0fsuch, for instance, as zirconium, yttrium, cerium and thelike--considerable difficulty has been experienced in making theconnections between the ends of the glowers and the leading-in Wiressufficiently intimate and strong to constitute a durable and efficientunion. It has been proposed to wind a fine platinum Wire about each endof the glower and to cover this small coil of platinum wire with a pasteformed of materials similar to those of the glower itself.

It has been found that such terminals are not always reliable and thatthey sometimes break away from the glower.

The object of the present invention is to obviate the insufficiencies ofthe terminal connection described and to provide a more lasting andefficient union between the leadingin wires and the'end of the glowersby means which will be hereinafter described. The first step in theprocess of accomplishing this result usually consists in applying to theends of the glowers beads or enlargements formed of chalk-like porousmaterials, these beads or enlargements being applied either by formingthem independently of the glowers and afterward molding and pressingthem into shape on the ends of the glowers or by adding them in the formof a paste to the glower ends either by dipping or by the use of a brushor other convenient means. When the beads or enlargements of chalk-likematerials have been thus applied to the glower ends, they are subjectedto the action of an oxyhydrogen flame or its equivalent a sufficientlength of time to thoroughly bake the material. The beads orenlargements are thus rendered sufficiently hard to preclude anymaterial danger of destruction during sub-- sequent manipulation. I thenusually apply the leading-in wires by fusing them upon theseenlargements by means of some conducting alloy-such as copper platinum,nickel plati' num, manganoxid platinum, or the like. I have found thatby treating a porous chalklike bead of this sort after it has beenapplied to the ends of a glower with heat sulficient to bake it therewill be i no further shrinking of the bead, and any union which I makebetween such a bead and a leadingin Wire is well suited to remainunbroken and to maintain itself under all the conditions of actualoperation.

I have obtained excellent results from the oxids of calcium, magnesium,and kaolin, also of zirconium, yttrium, cerium, and the like. A goodmixture may be formed, for in stance, by mixing kaolin with water, anddextrine or kaolin and calcium oxid mixed totogether with a suitablebinding material may be employed, or kaolin, calcium oXid, and magnesia.These and other earth oxids, such as mentioned, may be used eithersingly or in combination with each other and with a suitable bindingmaterial.

In the drawings Which accompany this specification, Figures 1, 2, 3, and4: illustrate different stages in the manufacture of the glowers and inthe process of applying the terminals and attaching the leading-inWlI'GS.

Referring to the drawings, A, Fig. 1, represents a glower composed of arare earth or a mixture of rare earths and having on its end beads orenlargements a a. The process by which the enlargements a (t are formedor placed upon the ends of the glower is preferably one of thefollowing-t-hat is to say, either abead of chalk-like porous material isformed independently of the glower and molded and pressed upon its ends,or the ends of the glower are dipped in a paste of such chalklike porousmaterial enough times to make the beads or enlargements of the sizedesired, or such a paste has been added with a brush until the properthickness of chalk-like material has been added to the ends of theglower.

The glower, as it appears in Fig. 1, with the beads attached, is thentreated, as is shown in Fig. 2, by being baked in an oxyhydrogen flameor its equivalent, which process serves not only to bakethe beads, asdescribed, but also to bring about, by means of the-heat applied, aperfect union between the beads and the ends of the glower.

The glower after treatment by heat, as illus trated in Fig. 2, isbrought into contact at its ends with the end of a leading-in wire 6,Fig. 3, a conducting alloy f, of copper platinum, manganoxid ofplatinum, or the like, being applied simultaneously therewith or as aprevious step in the process. Being subjected to heat in the presence ofsuch a conducting alloy the end of the glower and the end of theleading-in wire become firmly united, and in practice I find that theunion thus made is electrically adequate and mechanically strong andlittle liable to rupture.

In Fig. 4 I show a glower in its complete state and having theleading-in wires attached as described in the foregoing specification.

It will be observed that the material constituting the solder or meansof connection between the leading-wires and the ends of the glowerextends over a suflicient surface to aftord a good mechanical connectionbetween the leading-wires and the glower-terminals. This device servesalso to improve the electrical union of the two elements broughttogether in this way.

' While the chalk-like material will usually appear as beads orenlargements on the ends of the glowers, yet the object sought to be attained is ultimately the providing of a glowerterminal to which theleading-wires can be readily and (lurably attached. Terminals of suchmaterial appearing in any other form than that of beads or enlargementswould be quite within the scope of the present invention.

Should the leading-wire be of a metal other than platinum, the alloy maywell contain as one of its constituents some other metal as a substitutefor the platinum.

The apparatus herein referred to is not claimed in this application, butforms the securinga permanent union between the leading-wires and theglower-terminals in lamps of the type described, which consists 1nsecuring to the ends of the glowers a chalk-like porous material, thenbaking the same upon the said ends and attaching the leading-in wires tothe baked material by any suitable f conducting-solder.

2. The hereinbeforedescribed method of manufacturing glowers forelectric lamps which consists in making a strip, rod or other shapedincandescing body of rare earths or a mixture thereof, applying to theends thereof beads or enlargements of chalk-like porous material, andthen baking the said beads or enlargements.

3. The hereinbeloredescribed method of attaching a lead-wire to a glowerhaving a terminal in form of a baked porous material which consists inapplying the end of the leading-Wire to the said terminal and heatingboth the terminal and the end of the wire in the presence of a suitableconducting-solder.

at. The hereinbefore-described method of uniting the terminals of aglower for incandescent lamps to the leading-wires which consists informing upon the said glowers suitable terminals of baked porousmaterial which is a non-conductor when cold and attaching the saidleading-wires to the said terminals through the medium of a materialserving both as a conductorof electricity and as a good mechanicalconnection between the elements.

Signed by me at Pittsburg, Pennsylvania, this 18th day of April, 1899.

MARSHALL W. HANKS. Witnesses;

WESLEY G. CARR, H, G. TENER.

